Transmission



Oct. 10, 1950 P. ALTMAN mm.

TRANSMISSION 4 Sheets-Sheet 1 Filed Oct. 18, 1946 q HHI 0d. 10, 1950 ALTMAN ETAL 2,525,575

TRANSMISSION Filed Oct. 18. 1946 4 Sheets-$heet 2;

FEE. E.

INVENTOR. Pefer AV/mafl BY Md/VE/fi' 54km" #ML&W

Oct. 10, 1950 P. ALTMAN ETAL 5,

TRANSMISSION Filed Oct. 18. 1946 4 Sheets-Sheet 5 Q v llllxw INVENTOR. Ps'fer @V/man y Way/mm (1. Baker MezW Oct. 10, 1950 P. ALTMAN ETAL TRANSMISSI ON Filed Oct. 18. 1946 5 4 Sheets-Sheet 4 FIE-.4.

FIE-.5. I00? n P. E RAM m WW m wd 5 A mflm w 4 PM Y B Patented Oct. 10, 1956 TRANSMKSSION Peter Altman, Detroit, and Malvern S. Baker, assignors to Continental Motors Corporation, Detroit, Mich., a corpora- Muskegon, Mich,

tion of Virginia Application October 18,1946, Serial No. 704,200

4 Claims.

This invention relates to power transmission apparatus, especially to power transmissions of the automatic type as are used on self-propelled vehicles.

It is desirable in automotive vehicles requiring a variable gear ratio between the power plant and the rear wheels, to provide for automatic means of varying the ratio. It is further de sirable that the gear ratio be varied without interrupting the drive.

It is an object of this invention to provide a transmission of the type described in which the gear ratio between the engine and the propeller shaft may be varied from a maximum to direct drive, and that this variation may be accomplished with a minimum of attention by the operator of the vehicle and without interrupting the acceleration of the vehicle. It is a further object of the invention to accomplish the foregoing in a manner which takes into account the load put on the engine by the vehicles resistance to acceleration.

The foregoing objects are accomplished in a transmission of the planetary type in which the gear ratio is varied from a maximum to direct drive by automatic controls responsive to speed and torque.

In the drawings:

Fig. 1 is a view in sect on on line ll of Fig. 2.

Fig. 2 is a view in section on line 2--2 of Fig. 1.

Fig. 3 is a view in section on line 3-3 of Fig. 1.

Fig. 4 is a view in section on line 4-4 of Fig. 1, and

Fig. 5 is a schematic diagram of the two-stage governor.

An input shaft 2 is shown as being conn cted to del ver power to a planetary gear train. Shaft 2 drives the power or sun gear 4 of the planetary gear train. Meshing with power gear 4 is a second gear 6 which is a planet gear of the planetary gear train. Integral with planet gear 6 is a second planet gear 8. Gears 6 and 8 are mounted on shaft ID for rotation in planet carrier [2 about their own axis.

Planet carrier [2 is mounted for rotation about the axis of power gear 4. Carrier I 2 has only limited rotation in one direction, this limitat on being accomplished by a one-way brake and bearin combinat on indicated generally at M.

A brake is provided to prevent rotation of gears l and 8 about their axis. This brake may be any suitable type shown here in the form of a cone about the axis of shaft l0.) Engaging element I3 is movable axially of shaft I 0 by means of piston 20, which is reciprocable in cylinder 22; Hydraulic fluid may be supplied to cylinder 22 from any suitable source.

Planet gear 8 meshes with a sun gear 24 which is connected to output shaft 25 through a second planetary gear train described in detail below, through output sun gear 26 and intermediate shaft 21, and through the reversing gear train comprising shifter gear 28, gear 30, and the plurality of gears shown rotatable on counter shaft 32. Shifter gear 28 is mounted to be reciprocated axially by shifter bar 34. The re verse gear train is shown in its position for forward drive. Intermediate shaft 21 is held against backward rotation by any suitable one-way clutch such as that indicated generally at 36. Similarly, sun gear 24 is held against reverse rotation by a one-way clutch 38.

Sun gear 24, referred to above, is shown as being integral with intermediate shaft 32. Sun gear 44 of the second planetary gear trainis mounted for direct drive by shaft 42. Meshing with sun gear 44 is a planet gear 48; integral with planet gear 66 is another planet gear 48. Gears 46 and 48 are mounted for rotation with shaft 50 about their own axis in planet carrier 52. Planet carrier 52 is limited in its rotation in one direction by a suitable one-way brake indicated generally at 54.

A brake is provided to prevent rotation of gears 45 and 48 about their own axis. This brake may be any satisfactory type, such as the cone clutch shown, or a multiple disc clutch or the like, having a rotat ng element 56 and a non-rotating engaging element 58. Engaging element 58 is reciprocated axially by piston 68. P ston 60 is hydraulically actuated in cylinder 62 by any suitable fluid.

It will be seen that the two planetary gear trains are similar and that their associated planet gear brakes are substantially the same, as shown in Fig. 1. Also similar for the two gear trains are the means provided to limit backward rotation of the planet carriers. For a better understanding thereof, reference s ould be made to Figs. 1 and 3. Fig. 3 shows the one-way brake 54 and its associated mechanism, which is substantially the same as one-way brake M and its associated mechani m. i Planet carrier 52 is secured (as by splines 63) to and drives inner brake ring 64. Outer brake ring 66 forms with inner brake ring 64 an annular channel in which are disposed the brake elements. Brake ring 66 is splined as shown at 5? to control ring 58, on which are mounted a plurality of spring seats H1 and a valve actuating arm 12. Also mounted on and for movement with the control ring area plurality of slotted ears It. The slots 15 of ears Hi are adaptedto receive stop pins 18 which are mounted against movement in the spider 80, which forms a part of the transmission housing.

Springs 82 are compressed between spring seats it on control ring 58 and adiustable seats 8 Valve actuating arm 72 en ages the end of a piston valve as to close on orprevent communi cation between annular passages 38 and $63. Annular passage 85 is connected to be supplied with hydraulic fluid from an suitable source. The passage of fluid to the annular space 88 is controlled by a solenoid valve 92 which is actuated by an suitable speed responsive device such as governor 9 (Fig. 2). Annular passage 95 communicates with passage fill and permits the draining of hydraulic fluid from passage 9% with piston valve 88 in the position shown in Fi 3. Annular passage 98 is connected with cylinder 62. A similar valve means controls fiow of fluid under pressure to cylinder 22 which actuates pisten 20. I a,

Governorfil, driven by one of the gears rtating on counter shaft 32, may ,be any suitable two-stage governor, set to close or open two electric circuits at two different speeds. lhe details of this governor will not be gone into here because the governor details themselves are not the invention; A schematic diagram or the governor is shown in Fig. 5. As shown there, the governor comprises a split shafthaving two partstt and 98. A small ball Hill is associated with portion 96 of the shaft and the large ball I532 is associated with the split portion 98. Ball Hill, being lighter than ball lBZ, will require a hig e'r to close its contacts HM than will be re uired by ball I92 to close its contacts 556. It will, of course, be understood by those skilled in the art that the showing of Fig. is entirely schematic. F

In Fig. 3, as shown, the solenoid of valve 92 will be connected to be ener ized by the closing of contact'sidfil of governor 94. It will, of course, be understood that asimilar solenoid operated valve, shown dotted at lllt of Fig. 1, is provided for the control ofthe planetary gear train shown to the left of s ider BE! in Fig. 1. Valve i538 Will be c'o nnected to be energized b the closing of contacts we of governor 94.

At the too of Fig. 3 there is shown a small hydraulic consisting of a hollow piston Hi3 reci rocable in cylinder H2. At the right end of cylinder 5 l2 there is provided a smallbleed port H4. Piston H5 is en aged by lug M6 on control ring 63. In orderthat piston H0 may be sure to follow lug i is as springs 82 are compressed, a light spring l 53 is provided inside piston Hi3.

l 'ower may be sup lied to input shaft 2 through a conventional frict on clutch or through a fluid fly wheel and a disengaging clutch. 1

Operation In operation, shifter bar 3 is moved forward to put gear 28 in position for forward drive, as shown in Fig. 1. Power is supplied to input shaft 2 and gear l; Gear 4 drives gear 24 through the planet gears i3 and 8. The react on torque, or resistance to forward motion oifered by the vehicle, makes planet gears 6 and s and the planet carrier l2 want to rotate backwards or counterclockwise as seen in Fig. 3. (Remember that the planet gear train of carrier I2 is similar t the planet gear train and associated mechanism shown in Fig. 3.)

As the planet carrier [2 tends to rotate in the opposite direction from the rotation of power gear one-way brake i4 is set and control ring 63' is rotated to its limit against stop pins l8 compressing its associated torque reaction springs. (These will be substantially the same as springs 82 shown in Fig. 3.)

The angle through which control ring 68' rotates depends on the amount of resistance, or torque reaction ofiered by the vehicle. If the torque reaction is high, the control ring 58 will rotate enough to close the valve in the hydrau= lic line supplying fluid to cylinder 22. This valve will be similar to valve 86 shown in Fig. 3. Thus if the torque reaction is high, the closing of contacts m6 by governor ball I02 (at the first predetermined speed) ,energizes the solenoid of valve H58 but will not actuate the cone clutch brake mounted on shaft it} of planet carrier 52. As soon as the torque has fallen off sufiiciently, the torque reaction springs will rotate control ring 68f back far enough to permit passage of fluid through the valve, whereupon fluid will be ad mitted into cylinder 22. Piston 20 will then move to the right as seen in Fig. 1 and will set the cone clutch brake. With the brake set, the entire planetary gear train will rotate as a unit providing direct drive of intermediate shaft 42 by input shaft 2. The transmission will then be in s cond gear.

As the vehicle accelerates to reach the second predetermined speed, small ball ills closes contacts l M and energizes the solenoid to open valve 92. If the torque reaction is high, the tendency of planet carrier 52 to rotate in the reverse dirction will, through the one-way brake 54, som press springs 82 and close piston valve 86. Fluid will then not be able to reach cylinder 62 and the vehicle will continue to be driven through: the gear reduction of the second planetary gear train. As the torque reaction falls o'fi, springs 82 will rotate control ring 68 back far enough to permit fluid to pass from annular passage 38 annular passage as and thence to cylinder $2, moving piston 55 to the left and engaging the planet gear brake. Thereupon the planetary gear train of planet carrier 52 will rotate as a unit,

providing direct drive of output shaft 25, intermediate shafts 2'5 and intermediate shaft 42 by input shaft 2. In direct drive, all of the one-way clutches and brakes 38, i l, 54 and '36 will be unlocked to permit rotation in the forward direction of all elements. y

As the vehicle speed decreases, ball IUD of gov ernor 94 opens contacts I04 to tie-energize the solenoid of valve 92. Valve 92 thereupon closes, cutting off communication of cylinder 52 with the source of fluid pressure. Cylinder 62 is unloaded through annular passage 95 of piston valve 35 (Fig. 3), and disengaging spring I20 unlocks the planet gear brake, again permitting power to be transmitted through the gear reduction provided by the planetary train of carrier 52. When the speed decreases sufiiciently to open contacts H16 of governor 94, the solenoid of valye its is deen'ergi'zed, and cylinder 22 is out 01f from commun cation with the fluidpressure source. The planet gear brake of the first planetary train is then released, permitting drive through the gear reduction of that gear train.

We claim;

1. In a, transmission, an input sun gear and a drive shaft connected therewith, an output sun gear and a driven shaft connected therewith, a planet gear meshing with said sun gears, a rotatable mounting means for the planet gear whereby same may rotate about the sun gears, a transmission casing provided with means for rotatabl supporting said planet gear mounting means, a spring biased control ring supported by said casing for limited movement in one direction only and responsive to torque reaction of said driven shaft to rotate said control ring against the influence of the spring means urging said control ring in the opposite direction, fluid actuated brake means operable to lock the planet gear against rotation about its axis, a source of fluid pressure, a fluid line connecting said source of fluid pressure to said fluid actuated brake means, and a valve in said fluid line and actuated means, a control ring rotatably supported by said casing, spring means urging said ring in one direction, said ring moved in the opposite direction in response to a torque reaction of said driven shaft, and means controlled by said control ring to lock said planet gear against rotation about its own axis in response to a predetermined decrease in torque reaction.

3. In a transmission, an input sun gear and a drive shaft connected therewith, an output sun gear and a driven shaft connected therewith, a planet gear meshing with said sun gears, a rotatable mounting means for the planet gear whereby same may rotate about the sun gears, a transmission casing provided with means for rotatably supporting said planet gear mounting means, a control ring rotatably supported by said casing, spring means urging said ring in one direction, said ring moved in the opposite direction in response to a torque reaction of said driven shaft, and means controlled by said control ring to lock said planet gear against rotation about its own axis in response to a predetermined decrease in torque reaction, said means including a speed responsive device controlling admission of fluid under pressure to said lastmentioned means, and a valve intermediate said means and said fluid inlet controlled by said control ring to interrupt said fluid connection under the influence of relative high torque reaction and to open said fluid connection as the torque reaction is reduced to a predetermined degree.

4. In a transmission, an input sun gear and a drive shaft connected therewith, an output sun gear and a driven shaft connected therewith, a planet gear meshing with said sun gears, a rotatable mounting means for the planet gear whereby same may rotatate about the sun gears, a transmission casing provided with means for rotatably supporting said planet gear mounting means, a control ring rotatably supported by said casing, spring means urging said ring in one direction, said ring moved in the opposite direction in response to a torque reaction of said driven shaft, and means controlled by said control ring to lock said planet gear against rotation about its own axis in response to a predetermined decrease in torque reaction, said means including a speed responsive device controlling admission of fluid under pressure to said lastmentioned means, and a, valve intermediate said means and said fluid inlet controlled by said control ring to interrupt said fluid connection under the influence of relative high torque reaction and to open said fluid connection as the torque reaction is reduced to a predetermined degree, said valve comprising a, spring biased plunger, and an ear on said control ring actuating said valve plunger.

PETER ALTMAN. MALVERN S. BAKER.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 1,722,546 Wheeler July 30, 1929 1,795,464 Banker Mar, 10, 1931 2,022,689 Rainsford Dec. 3, 1935 2,122,701 Segard July 5, 1938 2,143,452 Reynolds Jan. 10, 1939 2,174,835 Rainsford Oct. 3, 1939 2,409,506 McFarland Oct. 15, 1946 

